Well, a lot depends on their setups.
Does this person have each snake in it's own enclosure ? Or are the babies all lumped together ?
Balls in general are docile snakes, so I think most will come around in time. I'm sure there are some out there who are just bad tempered, but I think they are few and far between.
Patience is key. That and not being afraid if getting bitten.
Gale